[nphard85]

chessprogramming.org is a treasure trove of knowledge on building chess engines. With its help, I wrote one in C++ a few years ago that got quite good (2100+ rating on FICS but that's nowhere close to the likes of Stockfish). In fact, writing a reasonably strong chess engine is straightforward (and incredibly fun) but at the top end of strength, there's immense depth, and after a point making improvements gets increasingly resource intensive (tuning params, running experiments to verify strength gain all takes a lot of compute).

Chess programming is also extremely addictive. On forums like talkchess.com, you see folks hanging out who have been doing it for decades (most of them are also super helpful to newbies).

[orlp]

> running experiments to verify strength gain all takes a lot of compute

Fun fact, in my master thesis I proved that quantum computers can verify this using quadratically fewer iterations than on a classical computer. That is, if it takes a classical computer c*n iterations to say with 99% certainty that agent A is stronger than agent B, a quantum computer can do it in d*sqrt(n) iterations, where c and d are agent-independent constants (obviously n is not agent-independent as two closely matched agents are harder to distinguish than a steamroll).

The number of qubits needed put this into the far future of quantum computing, but it's neat nonetheless.